Süleyman Sirri Demirsoy

Efficient implementation of digital filters using novel reconfigurable multiplier blocks

Reconfigurable multiplier blocks (ReMB) offer significant complexity reductions in multiple constant multiplications in time-multiplexed digital filters. In this paper the ReMB technique is employed in the implementation of a half-band 32-tap FIR filter on both Xilinx Virtex FPGA and UMC 0.18 /spl mu/m CMOS technologies. Reference designs have also been built by deploying standard time-multiplexed architectures and off-the-shelf Xilinx core generator system for the FPGA design. All designs are then compared for their area and delay figures. It is shown that, the ReMB technique can significantly reduce the area for the multiplier circuitry and the coefficient store, as well as reducing the delay.

Power analysis of multiplier blocks

In this study, three multiplier-blocks generated by different algorithms are analyzed for their power consumption via transition count based on their implementation on the Xilinx Virtex device. The high level Glitch-Path method, which is used for estimating the relative figures of transitions occurring at the outputs of the adders, has been refined for more accurate estimation and a new method GP Score is proposed. Several design issues are discussed regarding ways of reducing the transitions.

Transition analysis on FPGA for multiplier-block based FIR filter structures

This paper presents a study on the power consumption analysis of several multiplier-block based FIR filter structures. Transitions have been counted for the filter structures that were implemented on an FPGA device. The algorithms employed to generate the multiplier-blocks are compared with respect to their power performance. A new term, Glitch Path count, has been proposed and tested for use as an indicator of power consumption. This measure has been shown to be more correlated with the transition counts than the adder-count and logic depth approaches.

Design guidelines for reconfigurable multiplier blocks

The newly proposed reconfigurable multiplier blocks offer significant savings in area over the traditional multiplier blocks for time-multiplexed digital filters or any other system where only a subset of the coefficients that can be produced by the multiplier block is needed in a given time. The basic structure comprises a multiplexer connected to at least one input of an adder/subtractor that can generate several partial products, leading to better area utilization. The multiplier block algorithm complexity of a design increases logarithmically as the number of the multiplexers is increased. Design guidelines for the maximum utilization of the reconfigurable multiplier block structures are also presented.

Synthesis of reconfigurable multiplier blocks: part I - fundamentals

Reconfigurable multiplier blocks (ReMB) offer significant area, delay and possibly power reduction in time-multiplexed implementation of multiple constant multiplications. This paper and its companion paper (subtitled Part II - algorithm) together present a systematic synthesis method for single input single output (SISO) and single input multiple output (SIMO) ReMB designs. This paper presents the necessary foundation and terminology needed for developing a systematic synthesis technique. The companion paper illustrates the synthesis method through examples. The method proposed achieves reduced logic-depth and area over standard multipliers/multiplier blocks.

Synthesis of reconfigurable multiplier blocks: part - II algorithm

Reconfigurable multiplier blocks (ReMB) offer significant area, delay and possibly power reduction in time-multiplexed implementation of multiple constant multiplications. This paper and its companion paper (entitled part I - fundamentals) together present a systematic synthesis method for single input single output (SISO) and single input multiple output (SIMO) ReMB designs. This paper illustrates the synthesis method through examples. The companion paper presents the necessary foundation and terminology needed for developing a systematic synthesis technique. The proposed method achieves reduced logic-depth and area over standard multipliers/multiplier blocks.

Power consumption behaviour of multiplier block algorithms

Multiplier blocks have been used primarily for the reduction of circuit complexity. Using new algorithms, it has been shown that they can also be used for effective reduction of power consumption in digital filter circuits. In this paper, the new GP score method is used as a relative power measure to compare digital filter multiplier blocks designed using the BHM, RAGn and Cl algorithms.

Reconfigurable implementation of recursive DCT kernels for reduced quantization noise

Time multiplexed implementations of die recursive DCT processors are widely used in many multimedia and compression applications. The recently proposed three Goertzel kernels offer significant improvement (up to 90%) in the noise performance of the time-multiplexed architecture, allowing a reduction in word-length specifications. In this paper, a highly optimized reconfigurable DCT architecture is proposed that can perform the function of three different kernels (Type A, B and C) on Virtex FPGA.

Novel recursive-DCT implementations: a comparative study

Reports on a new recursive discrete cosine transform (DCT) architecture that is more efficient in terms of area and power in comparison with recently published recursive DCT architectures. Our approach employs A-, B- and C-type Goertzel filters. These three different realizations of Goertzel filters, together with a multiplier-less implementation of loop multiplications, are used so as to reduce the area, the multiplier delay and undesirable transitions, and hence the power consumption. The newly proposed DCT structure has been compared with conventional recursive implementations at different transform lengths, to observe that there are potential savings both in area and power.

A computationally efficient DAB bit-stream processor

This paper describes an MPEG (moving pictures expert group) audio layer II - LFE (lower frequency extension) bit-stream processor targeting DAB (digital audio broadcasting) receivers that will handle the decoding of the frames in a computationally efficient manner to provide a synthesis sub-band filter with the reconstructed sub-band samples. Focus is given to the frequency sample reconstruction part, which handles the re-quantization and re-scaling of the samples once the necessary information is extracted from the frame. The comparison to a direct implementation of the frequency sample reconstruction block is carried out to prove increased computational efficiency